A device commonly used on internal combustion engines to help reduce exhaust emissions is an Exhaust Gas Recirculation (EGR) valve. Nitrogen oxides (NOx) are formed when the temperatures in the combustion chamber get too high. The EGR valve recirculates engine exhaust gases into the intake stream of the engine, thus cooling the combustion process by several hundred degrees and reducing nitrogen oxides.
Gasoline engines rely on a vacuum generated from the engine for the EGR valve's actuation. However, diesel engines which do not produce vacuums must be equipped with vacuum pumps to operate EGR valves.
Vacuum operated EGR valves use diaphragms. The polymer diaphragms of vacuum EGR valves operate in a very harsh environment resulting in serious reliability problems.
The invention is directed to overcoming one or more of the problems set forth above.